Insulator



J. J. TAYLOR June 5, 1934.

INSULATOR Filed Feb. 17, 1933 Fig.1

Patented June 5, 1934 INSULA'IOR John J. Taylor, Barberton, Ohio,assignor to The Ohio Brass Company, Mansfield, Ohio, a corporation ofNew Jersey Application February 17, 1933, Serial No. 657,202

'7 Claims.

This invention relates to insulators and particularly to insulatorssubjected to bending moments, such those used for supporting catenarymessengers which carry trolley wires and commonly referred to ascatenary insulators. The invention is also adapted to a wide range ofuses and is applicable to insulators subjected to tension, compressionor bending moments.

One object of the invention is to provide an insulator which is adaptedto withstand bending moments, although it may be relatively short in thedirection of its axis so as to permit a plurality of units to beconnected together to provide insulators of varying lengths.

Another object of the invention is to provide an insulator which isadapted to withstand either tension or compression and also bendingmoments.

Another object of the invention is to provide an insulator of improvedconstruction and operation.

Other objects and advantages will appear from the following description.

The invention is exemplified by the combination and arrangement of partsshown in the accompanying drawing and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawing:

Fig. 1 is a fragmentary elevation with parts in section showing oneembodiment of the invention.

Fig. 2 is a fragmentary sectional view showing a modified form of theinvention.

Insulators as heretofore manufactured, and particularly insulators ofthe flat disc type, have been designed to withstand either tension orcompression but the individual units have not been adapted to withstandboth tension and compression nor to withstand bending moments. Thepresent invention provides an insulator unit, which although ofcomparatively short di mensions in the direction of its axis, willwithstand both tension and compression and also bending moments, and theunits are adapted to be connected together so that a stack of anydesired length in th direction of its axis may be built up. An insulatorof this kind is particularly well adapted for the suspension of catenarymessengers for suppor ing trolley wires, but there are of course manyother purposes to which the insulator may be putv In the form of theinvention shown in Fig. 1, the numeral 16 designates an insulating discof porcelain or other suitable material provided with an attachment headhaving a recess in which a metal pin 14 is secured by cement 15. A cap16 is secured to the outer surface of the attachment head by cement 17;the surface of the dielectric member being suit- 69 ably roughened toprovide a cementing surface 18. A cushion or gasket 19 may be in sortedbetween the rim of the cap 16 and the disc 10 to prevent the cap frombearing directly on the porcelain at this point. The cap 16 is providedwith two tapered bearing surfaces 29 21, inclined in opposite directionsrelative to the axis of the insulator. The inner surface of the cap ispreferably coated with wax, bitumen or other suitable material to prevent the cement from bonding to the surface of the cap. The pin 14 isalso provided with tapered bearing surfaces 22 and 23; the bearingsurface 22 being disposed in opposition to the bearing surface 20, andthe bearing surface 23 being opposed to the bearing surface 21.

The bearing surfaces of the cap and pin are disposed in symmetricalrelation to a plane perpendicular to the axis of the insulator andpassing through the apex of the angle formed by the surfaces 20 and 21.

When the insulator is placed under compression, the cement anddielectric material between the surfaces 21 and 23 will receive the loadon the insulator and the force of the load will be transmitted betweenthese two surfaces in a direction approximately normal to the bearingsurfaces. If the insulator is placed under tension, the load will bereceived by the bearing surfaces 20 and 22 and transmitted bycompression in the dielectric member substantially normal to these twosurfaces.

If the insulator is subjected to a bending moment, the insulator at oneside of the axis will be subjected to tension and the other side will besubjected to compression, so that one set of bearing surfaces willreceive the load at one side of the insulator and the other set ofbearing surfaces will receive the load at the opposite side of theinsulator. t is thus seen that irrespective of the nature of the loadplaced on the insulator, opposed bearing surfaces are provided forreceiving the force of the load and transmitting the load by compressionin the dielectric member. Since the dielectric member has its greateststrength in compression, this strength will be utilized to the bestadvantage for any form of load to which the insulator is subjected.

In order to prevent concentration of the load over the bearing surfaces22 and 23, these surfaces may be covered by a suitable resilient meansfor distributing the load. In l of the drawing, a helical spring 24,wound in successive convolutions upon the bearing surfaces, is shown forthis purpose.

The pin 14 is made comparatively large in diameter so as to provide acomparatively long radius from the axis of the pin to the bearingsurfaces 23 and 24, since this radius const. utes the lever arm for thebearing surfaces for resisting the bending moment upon the insulator.The increased diameter of the pin also proportionally increases theamount of bearing suri'ace for a given length of pin. It will be notedthat the insulator units are made coi'nparatively so that theirdimension is relatively short in the direction of the axis, and theunits are equipped with stud bolts 25 by which they may be assenwbled toform a stack of any desired length. Since the units themselves arecomparatively short in the direction of their axis, the length of thestack may be accurately adjusted to suit any conditions which may arise.

In the form of the invention shown in Fig. 2, the cap 26 is providedwith an inwar'ly projecting rib 2'7 which forms supplemental hear ingfaces 28 and 29. The bearing face 28 .vill supplement the bearing face30, and the hearing face 29 will supplement the hearing face 31. The pin32 is provided with hearing opposed to the bearing faces 29 and 31, andwith bearing faces 34 opposed to the bearing faces 28 and 30. The pin 32is also provided with radial resilient flanges 35 which provideresilient means for supporting a portion of the load, either in tensionor compression, and for thus relieving the pressure upon the bearingfaces 3'3 and 3441-.

This is particularly advantageous in the of a bending moment which tendsto place the greater stress upon the outermost bearing faces 33 and 34.The resilient flanges by ahsorlt' a a portion of this stress, preventexcessive pressure at the extremities of the pin which othe' wise wouldtend to produce failure in the diele tric member adjacent these points.

I claim:

1. An insulator comprising a dielectric member having an attachment headprovided with a eeess, a pin secured in said recess, a cap surroundingsaid attachment head and secured thereto, said pin and cap each having apair oi tapered bearing faces inclined in opposite directions relativeto the axis of the pin and disposed in symmetric relation relative tothe same plane normal to the axis of the pin. the bearing faces on saidpin being opposed to the bearing on said cap respectively.

2. An insulator comprising a dielectric member having an attachment headprovided. with a recess, a pin disposed in said recess, a capsurrounding said attacl'nnent head, said. pin and cap each having a pairof tapered bearing surfaces inclined in opposite directions relative tothe axis of the pin, cement interposed between said pin and capipectively and said dielectric member, the pea: surfaces on said pin andcap being arranad symmetrically relative to the plane normal to the axisof the insulator.

An insulator comprising a dielectric member, a pair of metal fittingsattached to said dielectric member and each having a pair of tapered being faces inclined in opposite direction ive to a common axis andarranged to said co] anon axis.

4. An insulator comprising a dielectric meinher ha\ an attachment headthereon proa pin secured in said resaid attachment head and d pin andcap each having inclined in opposite direst t0 the oi said insulator adisposed syinin: rically relative to the same no plane normal to saidaXi 5. An inst itor oinpl *ing a dielectric disc having an attachmenthead projecting from one thereof and having a recess entering said citeside of said disc, a pin "is, a cap rrounding said ereto, said pin andcap each having a pair of tapered bearing surfaces inclined in oppositedirections relative to the axis of said disc and c; sposed in symmetricrelation to the plane normal to said axis.

. An insulator co uprising a dielectric me na pin secured in -ed inopposite directions relthe at of the pin and dispo ed in symmetricrelation relative to the sam': one normal s, and a resilient ilar e onSl pin 1 a1 is for transto said a '1. An insulator comprising a die ec'ic disc having; an attacnn at head projecting at one side thereof, saiddisc having a recess therein open at ti side of said disc, a pindisposed iis .l\.l cap surrounding said head, said pin and cap having aplurality oi bearing faces inclined in opposite directions to tie VlS ofsaid disc and disposed L nnioti'ic rel on to the same plane normal tosaid cement securing said pin and cap to said attachment head, and aresilient flange pin extending substantially normal to and embedded saidcement for transng a portion cl. the load on said insulator.

JOHN J. TAYLOR.

, a portion of the load on said insulator.

